This invention relates to a flashlight in which light-emitting diodes (LED""s) are used as illuminants.
Due to the development of blue light-emitting diodes, it has now become possible to also develop white light-emitting diodes. The robustness and low energy consumption of white LED""s via-a-vis conventional incandescent light sources have led to the increased application of white or blue LED""s in flashlights. In this connection, such LED""s usually have different outside dimensions and connection designs than the conventional flashlight bulbs commonly in use. Thus, new casings usually have to be developed for using white LED""s, and moreover, the customer may have to purchase a new flashlight.
Therefore, the present invention provides a flashlight that can be equipped at a later time with LED""s as the illuminant means, or to use conventional illuminants, if necessary, or the novel LED""s.
Due to the fact that a connector piece is interconnected between the illuminant and the voltage supply in conjunction with a white LED that substantially corresponds to flashlight bulb socket, a novel adapter element has been developed that permits using a flashlight head with integrated LED""s in conjunction with a shaft piece of the type used in association with conventional illuminants. The batteries, which are usually connected with such a shaft piece in a non-detachable manner, therefore can be used also in the future in connection with the novel type of illuminant. If a completely new flashlight is purchased, it is possible for the customer to continue to use as a replacement, a battery with any shaft piece that he may already have.
A connector piece is provided in the head of the flashlight, which represents an advantageous further development of the invention. This connector piece is substantially comprised of a coaxial ring electrode having a structure that substantially corresponds with a conventional flashlight socket.
This connector piece is connected with the one or more illuminants via a small conductor board that is comprised of two electrically insulated areas. The advantage of such a flat conductor board is that several illuminants can be connected in parallel at the same time.
In another advantageous development of the invention, several white LED""s that are concentrically arranged in relation to an imaginary central axis, are integrated in the head of the flashlight.
The white LED""s are secured on an illuminant carrier. The LED""s are ideally cast directly together with this platform for supporting the illuminants, resulting in a strong element for retaining the illuminants that is by far superior to conventional flashlight sockets with respect to its durability and reliability.
On the side facing away from the shaft piece, the head of the illuminant is terminated by a transparent cover preferably made of plexiglas. This termination prevents foreign material from penetrating the head of the flashlight and thus contributes to the enhanced durability of the flashlight, particularly under difficult environmental conditions.
As a further development of the invention, biconvex lenses are shaped in the transparent plexiglas cover. The number of lenses preferably corresponds in this connection with the number of LED""s integrated in the head of the flashlight. The lenses are inclined toward one another in the sense of a focusing effect, so that the axes of the light beams of the lenses are focused. The inclination of the lenses is ideally selected depending upon the spacing of the illuminants from the lenses or the focal plane of the latter.
A preferably multi-cell nickel-metal-hydride battery for supplying the illuminants with current is preferably integrated within the casing of the shaft. These nickel-metal-hydride batteries have been found to be robust and permanently durable when they are preferably applied in the present case, if they are frequently recharged.
To recharge the batteries in the casing of the shaft, a charging plug is located on the surface of the shaft casing facing away from head of the flashlight. The batteries can be charged via conventional household plug sockets by means of the plug contact arranged on this side.
The charging plug can be sealed with a closing cap. This closing cap prevents the contacts of the plug from getting damaged, and improves the way in which the flashlight can be handled.
The shaft housing of the flashlight has a substantially rectangular cross section with rounded corners, which, in the area of the head of the flashlight, changes without steps into a square cross section. The square shape is particularly advantageous in connection with four white LED""s that can be concentrically disposed in a space-saving manner in relation to the central axis of the flashlight.
On the narrow sides of the aforementioned rectangularly-shaped cross section, ribs are provided on the outside surface that leads to an enhanced gripping and feel of the flashlight.
The head of the flashlight is connected in a detachable manner with the casing of the shaft via a interlocking contours.